Gas turbines manufactured in recent years have a combustion oscillation suppressing device (acoustic liner) on a transition piece of a combustor to suppress combustion oscillation generated in the combustor. A technique described in Patent Document 1 is known as a conventional gas turbine in which the above-described structure is adopted. A combustion oscillation suppressing device (modular resonator) of the conventional gas turbine is a modular resonator used in a combustion turbine power plant in which a compressor, a combustor assembly, a transition section, and a turbine assembly define a flow path. The modular resonator has a first member that has a size substantially smaller than the diameter of the flow path, and a plurality of openings therethrough; and a second member maintained spaced apart from the first member, and defining a gas space between the first member and the second member. The first member has the openings in fluid communication with the flow path.    Patent Document 1: Published Japanese Translation of PCT Application No. 2004-509313